The Effect of Denil Fishway Lengthon Passage of Some Nonsalmonid Fishes

EMIL SLATICK and LARRY R. BASHAM

Introduction

Steeppass Deml-type fishways havebeen used in Alaska and the PacificNorthwest to pass migrating adultsalmonids over small barriers(Zeimer, 1962, 1%5'; WashingtonDepartment of Fisheries, 1968). Denilfishways ranging from 9.1 m (30 feet)to 27.4 m (90 feet) long and angled atslopes of 19.7-26.2 percent have beenused successfully to pass cohosalmon, Oncorhynchus kisutch;sockeye salmon, O. nerka; and pinksalmon, 0. gorbuscha, in Alaska(Ziemer, 1962; footnote 1). The Na­tional Marine Fisheries Service(NMFS) has successfully used Demlfishways up to 20.1 m (66 feet) longto pass chinook salmon, O.tshawytscha; coho salmon; sockeyesalmon; and steelhead, Sa/mo gaird­neri, during experiments in the Co­lumbia River Basin, (Ebel, 1974;Slatick, 1975; Slatick et ai., 1975;

'Ziemer, G. L. 1%5. Steeppass fishwaydevelopment. Addenda to Inf. Leafl. 12. Un­pub!. manuscr., 5 p. Alaska Dep. Fish Game,Juneau, AK 99801.

ABSTRACT-This paper documentsthe success of passage of some non­salmonid fIShes through Denil-type steep­pass fISh ways of varying length and slope.Length ranged from 7.9 m (26 feet) to 20.1m (66feet), and slope ranged between 23.3and 28.7 percent. American shad, Alosasapidissima; common carp, Cyprinus car­pio; chiselmouth, Acrocheilus aJutaceus;northern squawfish, Ptychocheilusoregonensis; Pacific lamprey, Lampetratridentata; and suckers, Catostomus sp.,were observed at Bonneville and McNarydams on the Columbia River and LittleGoose Dam on the Snake River from 1971

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Thompson2).

While the NMFS was testing Demlfishways of varying lengths to passPacific salmon, many observationswere made on the passage of a varietyof nonsalmomd fishes, includingAmerican shad, A/osa sapidissima;common carp, Cyprinus carpio;chiselmouth, Acrochei/us a/utaceus;northern squawfish, Ptychochei/usoregonensis; Pacific lamprey,Lampetra tridentata; and suckers,Catostomus sp. This paper docu­ments the varying degrees of passagesuccess shown by the different speciesand points out a potential manage­ment implication.

Equipment and Procedures

The Deml fishway design used bythe NMFS was a Model A describedby Ziemer (1962). It was an aluminum

'Thompson, C. S. 1976. Evaluation of the adultsalmonid trap installed in the Bradford Island"A" branch fishladder, Bonneville Dam. Un­pub!. manuscr., 48 p., append. Northwest andAlaska Fisheries Center, NMFS, NOAA, 2725Montlake Blvd. E., Seattle, WA 98112. (prep.for U.S. Army Corps EngL, Portland, Oreg.under Contract DACW57-75-F-0547.)

to 1979. These fISh were successful inascending the 7.9 m (26-foot) flShway, andall but the common carp ascended the 15.2m (50-foot) fISh way. When the length wasextended to 20.1 m (66 feet), no Americanshad or resident freshwater fISh wereobserved ascending and passing throughthe Deni!. Salmonids and Pacific lamprey,however, were able to successfully passthrough all lengths of Deni! fISh waystested. These observations indicate thatDenil ladders of selected length could beused, if desired, to pass salmonid fIShesover small barriers while denying upstreamaccess to certain unwanted nonsalmonids.

flume made of sections that were 3.1m (10 feet) long, 0.56 m (22 inches)wide, and 0.7 m (27 inches) high con­taining internal baffles for control ofwater velocity (Fig. 1). Clearancewithin the baffles (open area) was0.36 m (14 inches) by 0.56 m (22inches). Sections were bolted orwelded together to achieve the desiredlength of ladder. The Deml fishwaystested ranged from 7.9 m (26 feet) to20.1 m (66 feet) long and were in­clined at slopes of 23.3-28.7 percent,depending on the experimental site.During operation, the Demls werecompletely filled with water and car­ried a flow of approximately 0.16m3/second (5.5 feet3 /second).

During the experiments, Demlswere installed in the regular fishwaysat Bonneville and McNary Dams onthe Columbia River and at LittleGoose Dam on the Snake River. AtBonneville Dam, Deml fishways werealso operated in the FisheriesEngineering Research Laboratory(Slatick, 1975). Observations on thepassage of nonsalmonid fishes oc­curred over an 8-year period, from1971 to 1979. Most of the data wereobtained between June and Augusteach year when maximum numbers ofresident and anadromous non­salmomd fishes were in the fish lad­ders.

Observations

Resident freshwater fish observedin the fish ladders at Bonneville Dam

Emil Slatick is with the Coastal Zone andEstuarine Studies Division, Northwest andAlaska Fisheries Center, National MarineFisheries Service, NOAA, 2725 MontlakeBoulevard East, Seattle, WA 98112. Larry R.Basham is with the Water Budget Center, 2705East Burnside, Suite 213, Portland, OR 97214.

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included common carp, northernsquawfish, and suckers. Both suckersand northern squawfish were reportedpassing through a 7.9 m long

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(26-foot) Denil with a slope of 24 per­cent at Bonneville Dam in 1971(Slatick, 1975). In 1979, the slope wasincreased to 27.8 percent, and com-

Figure 1. - View, above, isof 15.2 m (50-foot) longsteeppass Denil-typefishway in operation at Lit­tle Goose Dam. At left is aview of the unwatered 9.1m (3D-foot) long Denilfishway in the FisheriesEngineering ResearchLaboratory at BonnevilleDam.

mon carp, northern squawfish, andsuckers were observed passingthrough the Deni!.

A longer 15.2 m (50-foot) Denil(28.7 percent slope) was used at LittleGoose Dam on the Snake River, andnorthern squawfish, suckers, andchiselmouth were seen successfullypassing over this fishway over a 5-yearperiod. Common carp, however, wereobserved entering the Denil, but pro­ceeded only a short distance beforeeither jumping out or turning aroundand descending the ladder.

The length of a Denil apparentlyaffected the passage of carp; carpreadily passed the shorter fishway atBonneville Dam but rejected thelonger fishway at Little Goose Dam.Although the Denil fishways werelocated at two different dams, similarconditions existed: Carp were presentin the regular fish ladders, Denilslopes were identical, and the observa­tions were conducted during the sum­mer. The only known difference otherthan location was the length of theDeni!.

An even longer Denil adversely af­fected passage of both northernsquawfish and suckers. These fish,which had readily ascended the 15.2m (50-foot) fishway at Little GooseDam, rejected the 20.1 m (66-foot)Denil (27.3 percent slope) at Bon­neville Dam (footnote 2). It must beemphasized that these species oftentake up residence in main fishways atdams and mayor may not be activelymigrating during the summer. Theseobservations imply only that thosefreshwater species which passed overthe Denil fishways have the physicalability to do so.

American shad and Pacific lampreyare the only two anadromous non­salmonid species which migrate up theColumbia River past the hydroelectricdams. During the observation period,American shad were abundant in theColumbia River to above McNaryDam and were beginning to appear atLittle Goose Dam 112 km (70 miles)up the Snake River. Pacific lampreywere indigenous to the Snake River.Observations were made on the abilityof these fish to pass over Denils of

Marine Fisheries Review

varying length and slope. Several hun­dred shad were seen passing through a7.9 m (26-foot) long Denil fishway in­clined at slopes of 24 and 28.7 percentat Bonneville Dam and a 11.9 m(30-foot) long Denil with a 23.3 per­cent slope at McNary Dam. A fewshad were seen passing through thel5.2 m (50-foot) long Denil (28.7 per­cent slope) at Little Goose Dam, butnone passed through the 20.1 m(66-foot) long Denil (27.3 percentslope) used at Bonneville Dam.Pacific lamprey successfully passedthrough Denil fishways of all com­binations of length and slopes used.Lampreys passed through the longest(20.1 m) Denil tested at a rate of up to1,372 individuals in a 24-hour period(footnote 2).

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ConclusionsOur observations indicate that

American shad, common carp,chiselmouth, northern squawfish,Pacific lamprey, and suckers can as­cend and pass through a Denil steep­pass fishway of acceptable length andslope. The data also show that Denils~ 15 m long are unacceptable to com­mon carp, and Denils > 20 m long areunacceptable to northern squawfish,American shad, and suckers. Sincemigrating adult Pacific salmon,steelhead, and Pacific lamprey suc­cessfully pass through Denil fishwaysof up to 27 m in length, Denilladdersof selected lengths could be used, ifdesired, to pass salmonid fishes oversmall barriers, while denying up­stream access to selected species of

unwanted nonsalmonids, with the ex­ception of Pacific lamprey.

Literature CitedEbel, W. J. 1974. Marking fishes and inverte­

brates. III. Coded wire tages useful inautomatic recovery of chinook salmon andsteelhead trout. Mar. Fish. Rev. 36(7):10-13.

Slatick, E. 1975. Laboratory evaluation of Deniltype steeppass fishway with various entranceand exit conditions for passage of adultsalmonids and American shad. Mar. Fish.Rev. 37(9):17-26.

---=--=-=---=,---' D. L. Park, and W. J. Ebel.1975. Further studies regarding effects oftransportation on survival and homing ofSnake River chinook salmon and steelheadtrout. Fish. Bull., U.S. 73:925-931.

Washington Department of Fisheries. 1%8.Stream improvements and hydraulics. In DonReed (editor), Washington Department ofFisheries 1%8 Annual Report, p. 80--98.Olympia.

Ziemer, G. L. 1%2. Steeppass fishway develop­ment. Alaska Dep. Fish Game, Inf. Leaf!. 12,9 p.

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